The present invention relates to collection devices that arrange inside pipelines and similar fluid conveyance systems to trap samples and, more specifically, devices placed in stormwater pipelines to collect suspended sediment samples.
Inline sediment traps are one of many sampling tools utilized by municipalities, environmental agencies, and private parties to characterize piped pathways to receiving waters and to support ongoing contaminant investigations. A known sediment trap apparatus consists of a stainless steel bracket that bolts to the pipeline wall and the bracket supports a cylindrical housing fixture. The cylindrical housing fixture supports a 1-liter (L) high-density polyethylene (HDPE) sample bottle. The sample bottle is retained in the fixture by a securing band placed around the neck of the sample bottle, and the sample-bottle's open top arranges generally perpendicular to the flow of the effluent stream (see FIG. 1).
This known type of inline sediment trap is commonly deployed; yet, these trap deployments have captured insufficient volumes of stormwater solids to meet all analytical objectives, such as in a City of Portland (Oregon, USA) study where installed sediment traps were placed in a variety of locations within the stormwater conveyance system during the 2007 and 2008 wet seasons.
Despite the variety of known sediment traps in the art, there are several shortcomings that need to be overcome to provide a more efficient sample collection method and to provide more flexibility when installing devices in various diameter pipelines. These, and other, shortcomings and limitations of known collection devices were exposed during field use in Portland, Oreg., during the wet season in 2007, 2008, and 2009 when sediment samples were collected using various prior-art sediment trap designs. From this collection effort various observations of limitations in the known art were made and such limitations included that the bottle-type sediment traps required significant labor hours to install, and significant labor hours to separate the sediment from the fluid in the lab at the end of a deployment period before solids analysis. Other limitations include a large profile, and the resulting inability to be easily installed and removed or to capture adequate stormwater solids in small-pipe diameters (i.e., in pipe diameters less than 30 inches.
Other known collection devices include a system taught by Leoncavallo et al. in U.S. Pat. App. No. US 2004/0187611 published on 30 Sep. 2004. Leoncavallo describes a liquid sample collection system including a container having an interior reservoir for receiving a sample and a valve assembly that couples to the container. The valve assembly includes a separator configured to inhibit particulate material from entering the valve-housing inlet and reservoir.
Another known collection device, taught by Peters on 9 Jun. 1981 in U.S. Pat. No. 4,271,704, consists of a fluid sampling device including a body having a chamber and a control valve disposed in a control passageway and a sample valve disposed in a sampling passageway. Another device, in U.S. Pat. No. 4,303,533 to Fremont on 1 Dec. 1981, includes passing the stream through at least two contiguous layers of an open-celled compressible hydrophobic polymeric material. Yet another device, by Hannon on 14 Mar. 1995, U.S. Pat. No. 5,397,464, consists of a trough-type strainer box or basket with a mounting flange on its upper edge for supporting the basket in a floor sink to capture particulates. And another device, by Nurse, Jr. et al. on 28 Dec. 1999, U.S. Pat. No. 6,006,612, consists of a test assembly for sampling effluent waste water. The assembly includes two parallel testing lines, one of which includes a filter, the second of which contains—in one version—a second type of filter or—in a second version—no filter.
Further afield from a desired collection device, other teachings in the art include U.S. Pat. No. 4,590,810 issued on 27 May 1986 to Hunkin et al., which describes a device for collecting samples of water from wells. The device includes valves at both ends. And, U.S. Pat. No. 5,339,700 issued to Wright et al. on 23 Aug. 1994 describes a sample collector for drawing samples of a liquid by means of a pump near an inlet port.
Thus, there remains a need for a better sediment collection device that fits in various diameter pipelines including diameters less than 30-inches, requires less time to install and remove, improves the collection of sediment, and reduces laboratory processing time.